Load-Adaptive Slewing Cushion Valve for Stable Control Range

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Solution Overview

Problem

Construction machinery with large-inertia slewing mechanisms, such as truck cranes, experience reduced controllability and safety due to varying slewing inertias caused by different boom lengths and hoisting weights, leading to a small control range and significant stop impacts.

Innovation Solution

A load-adaptive slewing cushion valve and hydraulic system that maintains control range independence from load and minimizes stop impacts by using a pressure equalizing valve, solenoid reversing valves, and overflow valves to manage hydraulic pressure and flow, ensuring smooth slewing operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a conventional slewing control valve is used, then the system structure is simple, but the control range is small and stop impact is large under heavy load conditions

Engineering Contradiction:
Improvecontrol rangeVSAvoidvalve structure complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The slewing control valve is divided into multiple independent control channels (first control channel for port A, second control channel for port B). Each channel has its own control valve and pressure regulation mechanism, allowing independent optimization of each side's control characteristics without affecting the other, thereby expanding overall control range while managing complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control system incorporates dynamic pressure regulation through solenoid valves and pressure relief valves that automatically adjust oil pressure based on load conditions. The control valves can dynamically modify their opening degrees and flow characteristics in response to varying slewing loads, maintaining optimal control range across different operating conditions

Inventive Principle:
Principle #15Dynamics

2Reliability

If a conventional slewing control valve is used, then the device complexity is low, but the stop impact is large affecting safety

Engineering Contradiction:
ImprovesafetyVSAvoidvalve structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system incorporates cushioning mechanisms through pressure relief valves and controlled oil flow paths that gradually reduce oil pressure during deceleration phases. The control valves can pre-adjust flow rates to minimize impact forces before the slewing mechanism comes to a complete stop, thereby enhancing safety through proactive impact mitigation

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The dual-channel control system provides feedback mechanisms where pressure conditions in each channel are monitored and adjusted independently. The control valves respond to pressure feedback signals to modulate oil flow, ensuring smooth deceleration and reducing stop impact by continuously adapting to actual load conditions

Inventive Principle:
Principle #23Feedback

3Adaptability or versatility

If a load-adaptive slewing cushion valve is used, then the control range is maintained independent of load, but the device complexity increases

Engineering Contradiction:
Improveload adaptabilityVSAvoidvalve structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The adaptive control functionality is segmented into separate control channels, each equipped with its own pressure relief valve and control mechanism. This segmentation allows each channel to independently adapt to load conditions on its respective side, providing load adaptability without requiring a completely complex integrated system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control valves are designed with multi-functional capabilities, serving both as flow control elements and as load-adaptive pressure regulation elements. The same control valve structure handles both normal operation and load adaptation functions, reducing overall system complexity while maintaining versatility

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system enhances controllability and safety by maintaining consistent control range and reducing stop impacts, even under varying load conditions, thereby improving the operational stability of construction machinery.

Implementation Method 1

a port P1 of the oil inlet control valve is connected to the hydraulic oil tank by a pressure equalizing valve

Methodology Applied
Scientific EffectPressure equalization: Pascal's Law

Implementation Method 2

a first solenoid reversing valve, wherein an inlet of the first solenoid reversing valve is connected to the oil inlet P

Methodology Applied
Scientific EffectElectromagnetic actuation: Solenoid

Implementation Method 3

an inlet of the first solenoid reversing valve is connected to the oil inlet P, and an outlet of the first solenoid reversing valve is connected to a shuttle valve by means of a fifth one-way valve and to the hydraulic oil tank by means of a soft overflow valve

Methodology Applied
Scientific EffectPressure relief: Valve

Data Source

PatentEP4726219A1Load-adapting rotary cushion valve and load-adapting rotary hydraulic system
Publication Date: 2026.04.15 JIANGSU ADVANCED CONSTR MASCH INNOVATION CENT LTD
  • EP4726219A1 patent drawingFigure 1
  • EP4726219A1 patent drawingFigure 2
  • EP4726219A1 patent drawing

AI summary

Disclosed are a load-adaptive slewing cushion valve and hydraulic system. The load-adaptive slewing cushion valve comprises: an oil inlet P, configured to be connected to an oil supply pipeline of hydraulic oil; an oil return port T, configured to be connected to a hydraulic oil tank; a working oil port A, configured to be connected to one end of a slewing motor; and a working oil port B, configured to be connected to the other end of the slewing motor; wherein a port P of an oil inlet control valve is connected to the oil inlet P; a port P1 of the oil inlet control valve is connected to the hydraulic oil tank by a pressure equalizing valve; a port A of the oil inlet control valve is respectively connected to the working oil port A, an inlet of a first oil replenishment overflow valve, and a port A of an oil return control valve; a port B of the oil inlet control valve is respectively connected to the working oil port B, an inlet of a second oil replenishment overflow valve, and a port B of the oil return control valve; an outlet of the first oil replenishment overflow valve, an outlet of the second oil replenishment overflow valve, and a port T of the oil return control valve are respectively connected to the oil return port T. The present invention has the characteristics that the control range of a slewing control handle is not affected by a load and the stop impact is small.